发展农村教育 提高农业人口素质

“三农”问题已成为国民经济发展的制约因素，“三农”问题目前集中体现在农民增收难，农民增收难的直接原因在于农业人口素质偏低，使得农业、农民在竞争中处于劣势，因此，发展农村教育是解决中国农业、农村、农民问题的关键。     

淮北地区夏玉米田节肢动物优势种群灰色系统及时间生态位分析

摘要：通过对淮北地区夏玉米田节肢动物群落系统调查显示该地区：夏玉米田的主要害虫为玉米蚜、玉米叶甲、朱砂叶螨,主要天敌为草间小黑蛛、异色瓢虫、八斑球腹蛛、中华草蛉、龟纹瓢虫、微小花蝽、青翅隐翅虫、华姬猎蝽等。灰色度系统分析表明：与玉米蚜关联度较高的是中华草蛉（0.9432）,与朱砂叶螨的关联度高的是华姬猎蝽（0.9019）,与玉米叶甲的关联度高的是草间小黑蛛（0.9448）。对害虫和天敌的优势种群进行生态位分析,结果显示：玉米叶甲的时间生态位宽度最高,为3.4066,时间分布较宽;朱砂叶螨的时间生态位宽度最低,为2.1081,在时间上分布较为集中;中华草蛉和玉米蚜生态位重叠度较高,表明它们发生时间比较吻合,同步性较高;中华草蛉和玉米蚜的生态位相似性比例最高,为0.9929,表明中华草蛉和玉米蚜对时间资源的利用基本一致。通过分析表明,淮北地区夏玉米田的捕食性节肢动物对这三种优势害虫有着较为稳定、持续的控制作用。     

皖西南春棉田主要害虫和天敌种群时序动态格局

为探索直播春棉田害虫与其天敌之间的相互作用和竞争共存机制,采用直接观察法,系统研究了棉田主要害虫和天敌种群的时间动态变化,及其生态位宽度和生态位重叠值。研究结果表明,在直播春棉的不同生育期,棉田害虫和天敌的优势种不同。主要害虫和天敌的发生高峰期多集中在6—7月,而棉蚜高峰期在5月下旬,棉叶蝉高峰期在9月下旬。不同种群的时间生态位不同,害虫中棉盲蝽的生态位宽度最大,其次是棉铃虫,棉叶蝉和棉叶螨的生态位宽度较小;天敌中蜘蛛类天敌的生态位宽度最大,其次是小花蝽,黑襟毛瓢虫的生态位宽度最小。而黑襟毛瓢虫和瓢虫类天敌与棉蚜、棉叶螨生态位重叠度较大。因此,皖西南棉区直播春棉田可利用瓢虫类天敌抑制棉蚜和棉叶螨的危害,保护并利用好蜘蛛类天敌,需重点防治棉盲蝽和棉铃虫。     

新疆棉花主栽品种的抗蚜性及其机制研究

 对新疆棉区主栽的9个棉花品种进行了叶片形态特性、生化物质含量测定,结果表明,品种间抗蚜程度存在显著差异,新海21号抗蚜性最强,中棉所35和81-3感蚜。品种叶片的蜡质含量越高,对棉蚜的抗性越强,茸毛密度大,影响棉蚜的取食;游离棉酚和可溶性糖含量与抗蚜程度呈显著正相关;单宁含量与蚜害指数呈显著正相关;氨基酸中的谷氨酸含量越高,抗蚜性越强。逐步回归和相关分析发现,氮含量和氨基酸总量与抗蚜程度无明显相关性。品种的抗蚜性是多种特性综合作用的结果。     

Advantages of Different Tillage Systems and Their Effects on the Economically Important Pests, Thrips tabaci Lind. and Aphis gossypii Glov. in Cotton Fields

An experiment to assess advantages of different tillage and their effects on Aphis gossypii Glov. and Thrips tabaci Lind was conducted during the 2000 and 2001 cotton growing seasons in cotton fields at Adnan Menderes University, Agricultural Faculty Research Center, located in Ayd?n Province, Turkey. The tillage systems examined were conventional, strip, precision and ridge tillage. Two insect population densities were not affected by the type of tillage systems during either year. However, significant differences in populations were observed in thrips populations on 31 May 2000 and 18 May 2001 and aphid populations on 24 May 2000 and 11 May 2001. The results show that the highest yield was observed in all conservation tillage systems in 2000 and ridge tillage system in 2001. Early maturity was higher in both precision and ridge tillage systems. In addition, tillage systems did not affect fibre properties. As a result, the application of conservation tillage is more advantageous in cotton in respect of early maturity and total yield.     

转Bt基因棉田害虫和天敌组成及优势类群时序动态

在系统调查棉田节肢动物的基础上,就长江流域下游棉区种植转Bt基因棉对棉田害虫和天敌组成、数量以及时序动态的影响进行了分析。结果表明,转Bt基因棉田和常规棉田基本接近,均以棉蚜为害虫优势种,天敌优势种为草蛉、龟纹瓢虫、三突花蛛。按照营养关系分析表明,转Bt基因棉田和常规棉田均以植食性类群在营养层中占绝对优势,其次是捕食性天敌类群,而寄生性天敌较少;刺吸类害虫是植食性害虫的优势功能集团,瓢虫类、蜘蛛类和草蛉类为优势捕食性类群。转Bt基因棉能够显著减少棉田鳞翅目等靶标害虫类群的发生,而对其它非靶标害虫如刺吸类害虫以及棉田天敌发生没有显著影响。     

辽宁棚室西甜瓜蚜虫种群动态与药剂试验

为掌握瓜蚜的发生动态,完善农药减施技术,对辽宁省西甜瓜棚开展监测、调查与药剂试验.利用黄板监测棚内瓜蚜的发生动态,同时对棚内瓜蚜展开系统调查,并检验混配药剂的防控效果.结果 表明,北镇市大屯乡'脆宝'甜瓜蚜虫有翅蚜高峰在3月上旬,蚜量高峰在2月底;营口市熊岳镇'甜王'西瓜蚜虫有翅蚜高峰在5月中旬,蚜量高峰在5月上旬;凤...     

中国北方棉区转基因抗虫棉对棉苗蚜及其两种天敌的影响(英文)

2 0 0 1年田间小区试验研究了转 Bt基因棉和转双价基因 ( Bt+ Cp TI)棉对棉苗蚜及其天敌种群动态的影响 ;室内研究了转基因抗虫棉对两种棉蚜天敌的生物学影响。结果表明 ,转基因抗虫棉对棉蚜种群数量的影响不明显 ,未达显著水平。单作转基因棉田棉蚜发生期比麦套棉田提前 5天左右 ,发生数量是麦套棉田的 1 .6倍 ,表明麦棉套作可有效的控制苗蚜的为害。室内研究表明 ,异色瓢虫对用 Bt棉处理的的棉蚜的捕食量比对照增加 2 2 .0 % ,棉蚜茧蜂对用 Bt棉处理的棉蚜的寄生率降低 2 3.5 %。     

Preliminary Study on Metabolic Resistance Mechanism of Aphis craccivora in Intercropping Field of Cotton and Peanut to Imidacloprid

[Objective] This study aims to explore the difference of imidacloprid resistance between Aphid gossypii and Aphid craccivora in intercropping field of cotton and peanut, and the mechanism of imidacloprid resistance to A. craccivora, so as to scientifically control these pests and to effectively avoid the rapid development of the resistance to imidacloprid. [Method] Two A. gossypii field populations and two A. craccivora field populations were collected from intercropping field of cotton and peanut in Juye and Linqing county of Shandong province, China. The bioassay experiment with two A. gossypii field populations, the bioassay and synergism experiment in two A. craccivora field populations were performed by the leaf dipping method. In addition, the activities of carboxylesterase (CarE), glutathione S-transferase (GST) and cytochrome P450 monooxygenase (P450) were assayed in the susceptible strain and two field populations of A. craccivora. [Result] Two A. gossypii field populations from Linqing and Juye exhibited moderate levels of resistance to imidacloprid, with the resistance ratios of 43.2- and 54.6-fold, while two A. craccivora field populations from Linqing and Juye showed susceptible and low level of resistance to imidacloprid, with the resistance ratio of 3.7- and 8.3-fold, respectively. According to the synergistic experiments, PBO and DEM significantly synergized imidacloprid in A. gossypii field population of Juye with the synergistic ratio of 3.63- and 1.95-fold, respectively, and TPP had no effect on imidacloprid toxicity. In A. craccivora field population of Linqing, PBO significantly synergized imidacloprid with the synergistic ratio of 3.05-fold, and DEM and TPP had no effect on imidacloprid. Further enzyme activity tests revealed that the activities of P450 and GST in Juye A. craccivora population were significantly higher than susceptible strain, and the activity of CarE had no significant difference between Juye A. craccivora population and susceptible strain. However, the activity of P450 in Linqing A. craccivora population was higher than susceptible strain, and the activities of CarE and GST had no significant differences. [Conclusion] Sensitivity of the two aphids in intercropping field of cotton and peanut to imidacloprid were greatly different, and P450 and GST may play an important role in resistance of A. craccivora to imidacloprid. The results are valuable for reasonable use of pesticides to delay the development of pesticide resistance of two aphids.     

安阳棉蚜寄主专化型及其形成机制初步分析

为了解安阳地区棉蚜寄主专化型情况,进行了棉蚜不同寄主转接的适合度测定。结果显示,棉花上与黄瓜上的棉蚜相互转接后其存活率及繁殖力均明显下降,不能建立种群;棉花上的棉蚜转接到西葫芦上时,其存活率及繁殖力与其原寄主无显著差异;黄瓜上的棉蚜转接到西葫芦上时,其净增殖率及内禀增长率均显著地高于其原寄主;黄瓜上棉蚜对西葫芦的适应性比棉花上棉蚜强。表明安阳地区棉蚜存在黄瓜和棉花两种寄主专化型,且都可以利用西葫芦。进一步对3种植物苗期叶片游离氨基酸进行测定,结果显示,游离氨基酸种类及总量均在西葫芦中最多,棉花中次之,黄瓜中最少。寄主植物游离氨基酸种类及含量的多少会影响棉蚜的生长与繁殖,可能是棉蚜寄主专化型形成的影响因素之一。     

25%异丙抗蚜烟剂防治黄瓜蚜虫简报

试验表明,25%异丙抗蚜烟剂对黄瓜蚜虫有良好防效,且施用方便,生产中适宜用量为3.0~4.5㎏/hm2。在推荐用量范围内对黄瓜安全。